编辑后保留突出显示的文本颜色(Retain highlighted color of text after editing)

 在删除前面的行内容后，无法保留我在我的文本上设置的RichTextBox中突出显示的效果。 
 
 无论我从控件中删除多少文本，它总是删除自定义SelectionColor和SelectionBackColor我设置为已包含在其中的文本。 
 
 我的删除方法代码： 
 
private void btnRemove_Click(object sender, EventArgs e)
{
    //Remove selected line from RichTextBox
    richTextBox1.Text = richTextBox1.Text.Remove(richTextBox1.Text.Length - 1, 1);
    //Remove all blank lines remaining after deletion                  
    richTextBox1.Text = Regex.Replace(richTextBox1.Text, @"^\s*$(\n|\r|\r\n)", "", RegexOptions.Multiline);
}
 
 我想在这里删除的字母数是1，因为单词“AND”是通过剪贴板粘贴方法插入的简单图像。 
 
  

Cannot keep the highlighted effect I set in my RichTextBox on my text after removing content of a line in front of him. 
 
No matter how much text I remove from the control it always removes the custom SelectionColor and SelectionBackColor I set to a text already contained in it.
 
Code of my Removal method:
 
private void btnRemove_Click(object sender, EventArgs e)
{
    //Remove selected line from RichTextBox
    richTextBox1.Text = richTextBox1.Text.Remove(richTextBox1.Text.Length - 1, 1);
    //Remove all blank lines remaining after deletion                  
    richTextBox1.Text = Regex.Replace(richTextBox1.Text, @"^\s*$(\n|\r|\r\n)", "", RegexOptions.Multiline);
}
 
The number of letters I want to remove here is 1 as the word "AND" is a simple image inserted by means of Clipboard Paste method.
 

原文：https://stackoverflow.com/questions/37064223